Compressor discharge muffling means

ABSTRACT

A hermetic motor-compressor unit including a cylinder block having integrally formed silencer chambers between the outer wall of the block and the cylinder wall, provided for attenuating the sound produced by the pulsating characteristic of the discharge gas. The integrally formed chambers include relatively restricted portions and relatively expanded portions.

United States Patent [191 Buonocore et a1.

[ 1 COMPRESSOR DISCHARGE MUFFLING MEANS [75] Inventors: Salvatore Buonocore, East Syracuse;

Harvey G. Stenger, Skaneateles;

George T. Privon, Camillus, all of [73] Assignee: Carrier Corporation, Syracuse, NY. [22] Filed: Dec. 10, 1970 [21] Appl. No.: 96,792

[52] US. Cl. 181/36 R, 417/312 [51] Int. Cl. Fln 3/06 [58] Field of Search 181/35 R, 35 C, 36 R,

[56] References Cited UNITED STATES PATENTS 3,197,127 7/1965 Valbjorn 417/312 3,220,639 11/1965 Chew 417/312 X 3,250,461 5/1966 Parker 417/312 3,401,873 9/1968 Privon 417/312 X 3,676,021 7/1972 Warner 417/312 X 1,665,871 4/1928 Wood 181/36 R 3,171,506 3/1965 Hald ..181/61X 2,096,052 /1937 McMahon 181/36 A 2,200,222 5/1940 Tarleton 181/36 R 2,496,676 2/1950 Rawson 181/42 X 3,158,222 11/1964 Richmond 181/61 X Jan. 15, 1974 3,177,973 4/1965 Blues 181/40 X 3,193,193 7/1965 Jerteis 181/40 X 3,204,619 9/1965 Rubinowitz et a1. 181/40 UX 3,224,527 12/1965 Waldron 181/36 A 3,404,749 10/1968 Miller et a1. 181/40 FOREIGN PATENTS OR APPLICATIONS 1,358,426 3/1964 France 417/312 1,001,038 8/1965 Great Britain 1,368,204 6/1964 France 181/35 C 464,508 8/1928 Germany 181/40 23,318 1904 Great Britain 181/61 225,363 12/1924 Great Britain 181/57 603,238 3/1960 ltaly 181/36 D 216,897 12/1968 U.S.S.R 181/40 Primary ExaminerRichard B. Wilkinson Assistant Examiner-John F. Gonzales Att0rney-Harry G. Martin, Jr. and .1. Raymond Curtin [57] ABSTRACT A hermetic motor-compressor unit including a cylinder block having integrally formed silencer chambers between the outer wall of the block and the cylinder wall, provided forattenuating the sound produced by the pulsating characteristic of the discharge gas. The integrally formed chambers include relatively restricted portions and relatively expanded portions.

2 Claims, 4 Drawing Figures n (a J PAIENTEUJAN 1 51914 3.785453 7 SHEET 1 0F 3 21 h 4s 1 l INVENTORS SALVATORE BUONOCORE ATTORNEY PATEMTEU 51974 3.785.453 I SHEEI 2 UP 3 INVENTORS 4 SALVAT BUONOCORE FIG 2 HARV G.STENGE R v BY GEORGE T. PRIVON ATTORNEY .sumanr- FIG. 4

INVENTORS SALVATORE BUONOCORE HARVEY G. STENGER BY GEORGE T. PRIVON COMPRESSOR DISCHARGE MUFFLING MEANS BACKGROUND OF THE INVENTION Utilization of hermetic motor-compressor units for small air conditioning applications, such as room units, has proven to be highly acceptable and satisfactory.

In recent years, such units have become increasingly compact in size, sometimes to the detriment of operating performance. It is desirable to muffle the sound produced by the strokes of the compressor piston. However, due to the desirability of compact motorcompressor units, discharge muffling means occasionally have been eliminated.

Alternatively, where discharge muffling means have been included, such means have usually been separate components, thereby increasing the cost and size of the motorcompressor units.

It is an object of this invention to provide a unique cylinder block which integrally incorporates discharge gas muffling means, thereby achieving desirable compactness and low cost without adversely affecting the sound attenuating characteristics compressor unit.

SUMMARY OF THE INVENTION This invention relates to hermetic motor-compressor units, which include novel discharge muffling means provided in a cast cylinder block. The cylinder block includes means defining the cylinder of the compressor. The outer wall of the cylinder block is connected to the cylinder defining means. The outer wall of the cylinder block is spaced apart from an integrally formed inner wall, and from the cylinder defining means.

A partition wall is disposed the space formed between the outer and inner walls of the cylinder block. The partition wall separates the space into silencer of the motorchambers comprising serially connected relatively restricted sections and relatively expanded sections. The gas discharged from the cylinder flows into the serially connected restricted and expanded sections whereby the sound caused by the pulsating characteristic of the discharge gas is attenuated. The gas is subsequently withdrawn from the space.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view of a motor-compressor unit including the cylinder block in accordance with our invention;

FIG. 2 illustrates an oblique view of the cylinder block;

FIG. 3 illustrates a further oblique view of the cylinder block; and

FIG. 4 is a sectional view of the cylinder block illustrated in FIG. 2 taken along line IVIV of the figure.

DESCRIPTION OF THE PREFERRED EMBODIMENT and an upper shell section 12 which are welded together. An electric motor generally indicated at 15 and a compressor generally indicated at 17 are disposed within shell 11. Compressor 17 is axially aligned with motor 15 and is disposed therebelow.

The motor compressor unit 10 is suspended within shell 11. A preferred suspension system is described in copending application Ser. No. 096,825, filed Dec. 10, 1970, in the names of Richard S. Abel] and George T. Privon. 7

Motor 15 includes stator 18 and rotor 20, the rotor being operably connected to drive crankshaft 22. The crankshaft is supported within cylinder block 24 of compressor 17. A more detailed description of the cylinder block will appear hereinafter.

The cylinder block defines the cylinders 27 of the compressor. Closing the cylinders are cylinder heads 26 and 28. The cylinder heads are more fully described in copending application, Ser. No. 096,824, filed Dec. 10, 1970, in the names of Richard S. Abel] and Douglas J. Ingalls. The cylinder heads are secured to the cylinder blocks by means such as screws 25. Pistons 46 are disposed within cylinders 27 for reciprocal movement therein. Any desired number of cylinders may be employed. Connecting the pistons to the eccentric portion of the crankshaft 22 are connecting rods 42 and wrist pins 44. The desired reciprocating movement of the pistons is obtained by rotation of the crankshaft as is obvious to those skilled in the art.

Referring particularly to FIGS. 2, 3 and 4 of the drawings, the novel cylinder block will be more completely described. Cylinder block 24 includes outer wall 50. Preferably cylinder block 24 is formed by casting. lntegrally formed with wall is wall means 70 which defines cylinders 27 of the compressor. Wall means 70 is spaced apart from wall 50.

Inner wall 51 is also integrally formed with outer wall 50. Inner wall 51 defines an opening for bearing 49, provided for journaling the lower portion of crankshaft 22.

Connecting inner wall 51 and outer wall 50 is partition wall 52, integrally formed with the inner and outer walls. Partition wall 52 includes orifices 53 and 54. Preferably orifice 54 has tubular member 55 inserted therethrough, to extend the effective length thereof for a reason to be more fully explained hereinafter.

Partition wall 52 separates the space between outer wall 50, inner wall 51 and wall means 70 into serially connected sections, respectively, sections 58, 59, and 61. As shown in FIG. 4, the sections vary in diameter from having a substantially large diameter at the outer portion thereof to having a substantially narrow diameter at the portion adjacent partition wall 52. Orifice 53 communicates sections 59 and 60; while orifice 54 communicates sections 58 and 61.

Communicating sections 58 and 59 is restricted portion 57 shown in FIG. 3. Section 59 is also in communication with section 63, via restricted portion 71, as shown in FIG. 3. Section 61 shown in FIG. 2, includes an orifice 56 which communicates the section with discharge tube 34. Section 61 is in communication with section 62 via restricted portion 72. The abovedescribed sections, orifices and restricted portions define a flow path for the discharge gas comprising a plurality of silencer chambers for attenuating the sound produced by the pulsating characteristic of the discharge gas.

Mounting feet 66 are integrally formed with block 24. Mounting feet 66 have two functions. Foremost, they provide a platform for the motor of the motorcompressor unit. The motor is secured to the mounting feet, for example, by bolts, mounted through holes 69.

Additionally, mounting feet 66 include holes 68 which are provided for receiving the springs of the suspension system shown in the aforecited suspension system patent application. Upper bearing cap 45 is screwed to the top portion of the cylinder block which has threaded holes 67, provided for receiving the screws.

The eccentric portion of crankshaft 22 is positioned to rotate in opening 73 of cylinder block 24.

The hermetic motor-compressor unit embodying our invention is typically employed in a mechanical refrigeration system. The refrigerant gas to be compressed enters into the shell of the compressor via line 29. The gas passes through inlet 29 and screen 31 and thereafter flows over the windings of motor to cool the same in a manner well known to those skilled in the art. Screen 31 is included to separate any undesirable solid particles which may be entrained in the entering refrigerant gas.

The refrigerant gas after having cooled the windings of the motor enters into the compressor portion of the unit via inlet tubes 30 and 32 disposed in the top portion of cylinder heads 26 and 28.

The refrigerant gas enters into each cylinder 27 of the compressor via suction ports (not shown) which are formed in valve plate 33. The gas, after it is compressed by operation of the piston, enters into the appropriate section of the cylinder head via discharge ports 48, formed in valve plate 33. Discharge valve 48 connected to valve plate 33 regulates the flow of gas from the cylinder.

Due to the pulsating characteristic of the flow of the discharge gas, it is desirable to attenuate the sound produced by such pulsating flow.

Referring specifically to FIGS. 2 and 4, the gas discharged from cylinder 27", after having passed into the appropriate portion of the cylinder head, thereafter flows into passage 60. As shown, passage 60 has an initial relatively wide diameter portion which thereafter becomes a relatively narrow diameter portion. The gas flows through orifice 53 into a relatively narrow diameter portion of section 59 and is then expanded into the relatively wide diameter portion of section 59. Referring to FIGS. 3 and 4, the gas then flows through restricted section 57 into section 58. Concurrently, the gas discharged from cylinder 27 shown in FIG. 3, after having passed into its appropriate section of its cylinder head, also passes into the wide diameter portion of section 58. The combined gas flow then passes through orifice 54, having tubular member 55 disposed therein, into the relatively narrow diameter portion of section 61. The gas in section 61 also flows via restricted section 72 into section 62 where it expands. Member 55 is provided in orifice 54 to increase the effective length thereof so as to increase the sound attenuating quality of the unit.

The gas thereafter flows into orifice 56 provided in section 61. Orifice 56 is in communication with discharge line 34. The line is connected to discharge outlet 70, provided for transmitting the compressed gas to the other component of the refrigeration system.

it should be noted that although only one tube 55 has been shown, it is within the scope of this invention for any number of similar tubes to be included in the various passages. It has been found that in the preferred embodiment one tube is only required to obtain the desired sound attenuation.

With respect to providing the necessary lubrication for the unit, oil is stored in sump 39 of the compressor which is defined by lower shell section 14. Oil pick-up tube 38 extends into the sump so as to have its inlet below the surface of the oil. The tube is press fitted into an appropriate aperture formed in the bottom of crank shaft 22. Thrust bearing 41 journals tube 38. During normal operation, rapid rotation of the tube caused by rotation of the crankshaft produces a vacuum at the tube s inlet, causing oil to flow thereinto. Internal bores (not shown) formed eccentrically relative to the center line of the crankshaft provide the necessary force for supplying the lubricating oil to the bearing surfaces such as bearing 43 formed in bearing cap 45. Transverse bores (not shown) communicate with the internal bores of the crankshaft for supplying the oil therefrom to the external bearing surfaces. Grooves 47 are provided on the outer surface of crankshaft 22 for the flow of oil to the bearings 43 and 49.

Undesirable sound produced by the pulsating nature of the discharge gas is attenuated by directing the gas through the serially connected relatively expanded and restricted portions of the silencer chambers formed in the space provided within the cylinder block. By providing the sound attenuating means integrally with the cast cylinder block, efficient sound attenuation is obtained without the necessity of providing an additional component, thus achieving the desired compactness for the unit without having a concomitant sacrifice in quality.

While we have described and illustrated a preferred embodiment, the invention is not limited thereto but may be otherwise embodied within the scope of the following claims.

We claim:

1. A cylinder block for a hermetic motor compressor unit operable to provide high pressure gas comprising:

a. wall means defining the outer wall of said cylinder block;

[2. cylinder defining means spaced radially inward from said wall means to define a plurality of cylinders, a substantially annular space being defined by said spaced apart wall means and cylinder defining means;

c. partition means extending transversely in said space between said cylinder defining means and said wall means to separate said space into a plurality of serially connected silencer chambers;

d. passage means provided for communicating said cylinders with selected portions of said space for passage of gas discharged from said cylinders into said space, the gas passing through said serially connected silencer chambers to attenuate the sound caused by the pulsating characteristic of the discharged gas, said passage means including a restricted portion extending radially outward from a selected one of said cylinders to provide communication between two adjacent silencer chambers, the gas discharged from one of said cylinders passing through said restricted portion to combine with the gas discharged from said other cylinder; and

e. means defining a discharge conduit connected to wherein said silencer chambers comprise sections havone of said silencer chambers for discharging the ing relatively wide diameter and relatively narrow digas from said cylinder block. ameter portions.

2. A cylinder block in accordance with claim 1 

1. A cylinder block for a hermetic motor compressor unit operable to provide high pressure gas comprising: a. wall means defining the outer wall of said cylinder block; b. cylinder defining means spaced radially inward from said wall means to define a plurality of cylinders, a substantially annular space being defined by said spaced apart wall means and cylinder defining means; c. partition means extending transversely in said space between said cylinder defining means and said wall means to separate said space into a plurality of serially connected silencer chambers; d. passage means provided for communicating said cylinders with selected portions of said space for passage of gas discharged from said cylinders into said space, the gas passing through said serially connected silencer chambers to attenuate the sound caused by the pulsating characteristic of the discharged gas, said passage means including a restricted portion extending radially outward from a selected one of said cylinders to provide communication between two adjacent silencer chambers, the gas discharged from one of said cylinders passing through said restricted portion to combine with the gas discharged from said other cylinder; and e. means defining a discharge conduit connected to one of said silencer chambers for discharging the gas from said cylinder block.
 2. A cylinder block in accordance with claim 1 wherein said silencer chambers comprise sections having relatively wide diameter and relatively narrow diameter portions. 